Ceres’ bright spots could be sign of geologic activity
- Scientists say the bright spots on dwarf planet Ceres can be divided into four different categories
- While Ceres was thought to be a ‘dead world,’ they say the spots indicate it may still be evolving
- Since the first spots were detected in 2015, the Dawn spacecraft has spotted more than 300
Mysterious bright spots dotting the surface of the dwarf planet Ceres have baffled scientists since they were first spotted two years ago.
NASA’s Dawn spacecraft captured the first images of two distinctly reflective areas in 2015 – and in the time since, scientists have detected hundreds more.
A new study reveals the bright spots can be divided into four different categories, offering evidence that the dwarf planet may not be a ‘dead world’ after all; instead, the experts say it could still be experiencing geologic activity.
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Mysterious bright spots dotting the surface of the dwarf planet Ceres have baffled scientists since they were first spotted two years ago. NASA’s Dawn spacecraft captured the first images of two distinctly reflective areas in 2015. A simulation of the bright areas of Occator Crater, Cerealia Facula in the center and Vinalia Faculae to the side, is pictured
THE ‘WEIRD WORLD’ OF CERES
Ceres is 590 miles (950 km) across and was discovered in 1801.
It is the closest dwarf planet to the sun and is located in the asteroid belt, making it the only dwarf planet in the inner solar system.
Ceres is the smallest of the bodies currently classified as a ‘dwarf planet’.
It lies less than three times as far as Earth from the sun – close enough to feel the warmth of the star, allowing ice to melt and reform.
Nasa’s Dawn spacecraft made its way to Ceres after leaving the asteroid Vesta in 2012.
There is high interest in the mission because Ceres is seen as being a record of the early solar system.
According to NASA, scientists have spotted more than 300 bright spots on Ceres.
Analyses since Dawn first arrived to the planet’s orbit have revealed more details on the processes by which they formed and changed over time, suggesting the world is still evolving.
‘The mysterious bright spots on Ceres, which have captivated both the Dawn science team and the public, reveal evidence of Ceres’ past subsurface ocean, and indicate that, far from being a dead world, Ceres is surprisingly active,’ said Carol Raymond, deputy principal investigator of the Dawn mission.
‘Geological processes created these bright areas and may still be changing the face of Ceres today.’
The first group of bright spots includes the most reflective material on the dwarf planet.
These bright spots are found on crater floors – such as the now famous examples in Occator Crater, which is home to two prominent bright areas.
The 6-mile-wide spot Cerealia Faculta sits at the center, and makes up a massive put with a dome inside.
A new study has found that the bright spots can be divided into four different categories, offering evidence that the dwarf planet may not be a ‘dead world’ after all; instead, the experts say it could still be experiencing geologic activity. Ceres’ 21-mile-wide Haulani Crater, pictured above, shows evidence of landslides from its crater rim
A slightly less reflective collection of features called Vinalia Faculae sits to the east of center.
In the second group, the bright material is collected along the rims of craters, and streaks down toward the floors.
According to NASA, impacts likely exposed the material that was already beneath the surface, or formed after a previous impact.
The third group is said to be found in material ejected when craters were formed.
And, the fourth category is reserved solely for a mountain known as Ahuna Mons.
NASA says this is the only case in which the bright material on Ceres is not affiliated with an impact crater.
Analyses since Dawn first arrived to the planet’s orbit have revealed more details on the processes by which they formed and changed over time, suggesting the world is still evolving. The Oxo Crater has a large ‘slump’
The fourth category is reserved solely for a mountain known as Ahuna Mons. NASA says this is the only case in which the bright material on Ceres is not affiliated with an impact crater
The region is thought to be a cryovolcano, which may have formed through the slow accumulation of icy material.
It’s thought that Ceres once experienced more impacts, billions of years ago.
During this time, the dwarf planet may have had thousands of bright areas.
Over hundreds of millions of years, however, the bright material likely mixed with the dark material that makes up the rest of the surface.
‘Previous research has shown that the bright material is made of salts, and we think subsurface fluid activity transported it to the surface to form some of the bright spots,’ said Nathan Stein, a doctoral researcher at Caltech in Pasadena, California.
In the Occator Crater, where the two bright spots are so different from each other, the researchers say a reservoir of salty water in the recent past could be to blame.
Vinalia Faculae may have formed from a fluid pushed up to the surface by a small amount of gas, much like the effect of champagne rushing to the top of a bottle.
This gas could have been water vapour, carbon dioxide, methane, or ammonia, according to NASA.
Cerealia Facula, on the other hand, is more elevated and brighter, suggesting it formed by different processes.
There, the material may have been like an icy lava, pushed up through fractures and swelling into a dome, NASA says.
In the time since the first two spots were found, scientists have detected hundreds more. According to NASA, scientists have spotted more than 300 bright spots on Ceres
Both, however, likely experienced periods of intermittent boiling, which deposited ice and salt particles on the surface.
It’s thought that the impact that formed the 57-mile-wide crater may also have created fractures, allowing liquid water to come through.
‘We also see fractures on other solar system bodies, such as Jupiter’s icy moon Europa,’ said Lynnae Quick, a planetary geologist at the Smithsonian Institution in Washington.
‘The fractures on Europa are more widespread than the fractures we see at Occator.
‘However, processes related to liquid reservoirs that might exist beneath Europa’s cracks today could be used as a comparison for what may have happened at Occator in the past.’
Courtesy: Daily Mail Online